You don’t even need treats, although they’re great reinforcers. You just need to be fun and interesting: Trot backwards with a toy. Celebrate with a play session when he catches up to you. Then do big circles in the yard. Reward puppy with treats or play. Or suddenly run away. Cheer when puppy zips after you!
You want to be teaching him that it’s good to stick close to the humans. It’s much easier to teach leash manners with that foundation.
Also, 8.5 weeks seems awfully young to be out and about, walking on the ground, for socialization. We did take Peggy to a cemetery around 9 weeks, but she didn’t need a leash. Not only were we faster than her still, she had that strong puppy instinct to stick close. A puppy wouldn’t survive long on their own and—genetically—they’re hardwired to know this!
At 12 weeks we started puppy class and leash manners.
You can put a leash on your puppy now for safety, but I wouldn’t try to walk him yet in any sort of linear way.
I can’t recall—is this your first dog? If so, be sure to work from a good puppy raising manual. I highly recommend Ian Dunbar’s Before And After Getting Your Puppy. It’s available as a book:
Before and After Getting Your Puppy: The Positive Approach to Raising a Happy, Healthy, and Well-Behaved Dog [Dunbar, Dr. Ian] on Amazon.com. *FREE* shipping on qualifying offers. Before and After Getting Your Puppy: The Positive Approach to Raising a Happy, Healthy, and Well-Behaved Dog
www.amazon.com
And it can also be read online for free:
I also recommend googling “puppy blues.” It’s a very real thing, and it’s nice to know you’re not alone when you’re feeling overwhelmed.
This stage of your puppy’s life will fly by.